summaryrefslogtreecommitdiff
path: root/include/trace/events
diff options
context:
space:
mode:
authorJan Kara <jack@suse.cz>2020-06-17 15:58:23 +0200
committerJens Axboe <axboe@kernel.dk>2020-06-25 21:06:11 -0600
commitf3bdc62fd82ed93dbe4d049eacba310de7eb2a6a (patch)
treeeefbacc996ba10e58a127a7a2df8924e4bbb0179 /include/trace/events
parent621c1f42945e76015c3a585e7a9fe6e71665eba0 (diff)
blktrace: Provide event for request merging
Currently blk-mq does not report any event when two requests get merged in the elevator. This then results in difficult to understand sequence of events like: ... 8,0 34 1579 0.608765271 2718 I WS 215023504 + 40 [dbench] 8,0 34 1584 0.609184613 2719 A WS 215023544 + 56 <- (8,4) 2160568 8,0 34 1585 0.609184850 2719 Q WS 215023544 + 56 [dbench] 8,0 34 1586 0.609188524 2719 G WS 215023544 + 56 [dbench] 8,0 3 602 0.609684162 773 D WS 215023504 + 96 [kworker/3:1H] 8,0 34 1591 0.609843593 0 C WS 215023504 + 96 [0] and you can only guess (after quite some headscratching since the above excerpt is intermixed with a lot of other IO) that request 215023544+56 got merged to request 215023504+40. Provide proper event for request merging like we used to do in the legacy block layer. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/trace/events')
-rw-r--r--include/trace/events/block.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 93b114226af8..34d64ca306b1 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -212,6 +212,21 @@ DEFINE_EVENT(block_rq, block_rq_issue,
);
/**
+ * block_rq_merge - merge request with another one in the elevator
+ * @q: queue holding operation
+ * @rq: block IO operation operation request
+ *
+ * Called when block operation request @rq from queue @q is merged to another
+ * request queued in the elevator.
+ */
+DEFINE_EVENT(block_rq, block_rq_merge,
+
+ TP_PROTO(struct request_queue *q, struct request *rq),
+
+ TP_ARGS(q, rq)
+);
+
+/**
* block_bio_bounce - used bounce buffer when processing block operation
* @q: queue holding the block operation
* @bio: block operation